From 0db8646d574c07c40793bad5e5ab768da6161628 Mon Sep 17 00:00:00 2001
From: Jeremy Soller <jeremy@system76.com>
Date: Thu, 5 Dec 2024 20:35:23 +0000
Subject: [PATCH 1/2] drivers/intel/dtbt: Add discrete Thunderbolt driver

Add a new driver for discrete Thunderbolt controllers. This allows using
e.g. Maple Ridge devices on Raptor Point PCH.

Ref: Titan Ridge BIOS Implementation Guide v1.4
Ref: Maple Ridge BIOS Implementation Guide v1.6 (#632472)
Change-Id: Ib78ce43740956fa2c93b9ebddb0eeb319dcc0364
Signed-off-by: Jeremy Soller <jeremy@system76.com>
Signed-off-by: Tim Crawford <tcrawford@system76.com>
---
 src/drivers/intel/dtbt/Kconfig     |   4 +
 src/drivers/intel/dtbt/Makefile.mk |   3 +
 src/drivers/intel/dtbt/chip.h      |   8 ++
 src/drivers/intel/dtbt/dtbt.c      | 199 +++++++++++++++++++++++++++++
 4 files changed, 214 insertions(+)
 create mode 100644 src/drivers/intel/dtbt/Kconfig
 create mode 100644 src/drivers/intel/dtbt/Makefile.mk
 create mode 100644 src/drivers/intel/dtbt/chip.h
 create mode 100644 src/drivers/intel/dtbt/dtbt.c

diff --git a/src/drivers/intel/dtbt/Kconfig b/src/drivers/intel/dtbt/Kconfig
new file mode 100644
index 0000000000..5c03a97db9
--- /dev/null
+++ b/src/drivers/intel/dtbt/Kconfig
@@ -0,0 +1,4 @@
+config DRIVERS_INTEL_DTBT
+	def_bool n
+	help
+	  Support for discrete Thunderbolt controllers
diff --git a/src/drivers/intel/dtbt/Makefile.mk b/src/drivers/intel/dtbt/Makefile.mk
new file mode 100644
index 0000000000..1b5252dda0
--- /dev/null
+++ b/src/drivers/intel/dtbt/Makefile.mk
@@ -0,0 +1,3 @@
+# SPDX-License-Identifier: GPL-2.0-only
+
+ramstage-$(CONFIG_DRIVERS_INTEL_DTBT) += dtbt.c
diff --git a/src/drivers/intel/dtbt/chip.h b/src/drivers/intel/dtbt/chip.h
new file mode 100644
index 0000000000..2b1dfa70a5
--- /dev/null
+++ b/src/drivers/intel/dtbt/chip.h
@@ -0,0 +1,8 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+
+#ifndef _DRIVERS_INTEL_DTBT_CHIP_H_
+#define _DRIVERS_INTEL_DTBT_CHIP_H_
+
+struct drivers_intel_dtbt_config {};
+
+#endif /* _DRIVERS_INTEL_DTBT_CHIP_H_ */
diff --git a/src/drivers/intel/dtbt/dtbt.c b/src/drivers/intel/dtbt/dtbt.c
new file mode 100644
index 0000000000..a54f0e213d
--- /dev/null
+++ b/src/drivers/intel/dtbt/dtbt.c
@@ -0,0 +1,199 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+
+#include "chip.h"
+#include <acpi/acpigen.h>
+#include <console/console.h>
+#include <delay.h>
+#include <device/device.h>
+#include <device/pci.h>
+#include <device/pciexp.h>
+#include <device/pci_ids.h>
+#include <timer.h>
+
+#define PCIE2TBT 0x54C
+#define PCIE2TBT_VALID BIT(0)
+#define PCIE2TBT_GO2SX			2
+#define PCIE2TBT_GO2SX_NO_WAKE		3
+#define PCIE2TBT_SX_EXIT_TBT_CONNECTED	4
+#define PCIE2TBT_OS_UP			6
+#define PCIE2TBT_SET_SECURITY_LEVEL	8
+#define PCIE2TBT_GET_SECURITY_LEVEL	9
+#define PCIE2TBT_BOOT_ON		24
+#define PCIE2TBT_USB_ON			25
+#define PCIE2TBT_GET_ENUMERATION_METHOD	26
+#define PCIE2TBT_SET_ENUMERATION_METHOD	27
+#define PCIE2TBT_POWER_CYCLE		28
+#define PCIE2TBT_SX_START		29
+#define PCIE2TBT_ACL_BOOT		30
+#define PCIE2TBT_CONNECT_TOPOLOGY	31
+
+#define TBT2PCIE 0x548
+#define TBT2PCIE_DONE BIT(0)
+
+// Default timeout for mailbox commands unless otherwise specified.
+#define TIMEOUT_MS 1000
+// Default timeout for controller to ack GO2SX/GO2SX_NO_WAKE mailbox command.
+#define GO2SX_TIMEOUT_MS 600
+
+static void dtbt_cmd(struct device *dev, u32 command, u32 data, u32 timeout)
+{
+	u32 reg = (data << 8) | (command << 1) | PCIE2TBT_VALID;
+	u32 status;
+
+	printk(BIOS_DEBUG, "dTBT send command %08x\n", command);
+	pci_write_config32(dev, PCIE2TBT, reg);
+
+	if (!wait_ms(timeout, (status = pci_read_config32(dev, TBT2PCIE)) & TBT2PCIE_DONE)) {
+		printk(BIOS_ERR, "dTBT command %08x send timeout %08x\n", command, status);
+	}
+
+	pci_write_config32(dev, PCIE2TBT, 0);
+	if (!wait_ms(timeout, !(pci_read_config32(dev, TBT2PCIE) & TBT2PCIE_DONE))) {
+		printk(BIOS_ERR, "dTBT command %08x clear timeout\n", command);
+	}
+}
+
+static void dtbt_write_dsd(void)
+{
+	struct acpi_dp *dsd = acpi_dp_new_table("_DSD");
+
+	acpi_device_add_hotplug_support_in_d3(dsd);
+	acpi_device_add_external_facing_port(dsd);
+	acpi_dp_write(dsd);
+}
+
+static void dtbt_write_opregion(const struct bus *bus)
+{
+	uintptr_t mmconf_base = (uintptr_t)CONFIG_ECAM_MMCONF_BASE_ADDRESS
+			+ (((uintptr_t)(bus->secondary)) << 20);
+	const struct opregion opregion = OPREGION("PXCS", SYSTEMMEMORY, mmconf_base, 0x1000);
+	const struct fieldlist fieldlist[] = {
+		FIELDLIST_OFFSET(TBT2PCIE),
+		FIELDLIST_NAMESTR("TB2P", 32),
+		FIELDLIST_OFFSET(PCIE2TBT),
+		FIELDLIST_NAMESTR("P2TB", 32),
+	};
+
+	acpigen_write_opregion(&opregion);
+	acpigen_write_field("PXCS", fieldlist, ARRAY_SIZE(fieldlist),
+			    FIELD_DWORDACC | FIELD_NOLOCK | FIELD_PRESERVE);
+}
+
+static void dtbt_fill_ssdt(const struct device *dev)
+{
+	struct bus *bus;
+	struct device *parent;
+	const char *parent_scope;
+	const char *dev_name = acpi_device_name(dev);
+
+	bus = dev->upstream;
+	if (!bus) {
+		printk(BIOS_ERR, "dTBT bus invalid\n");
+		return;
+	}
+
+	parent = bus->dev;
+	if (!parent || parent->path.type != DEVICE_PATH_PCI) {
+		printk(BIOS_ERR, "dTBT parent invalid\n");
+		return;
+	}
+
+	parent_scope = acpi_device_path(parent);
+	if (!parent_scope) {
+		printk(BIOS_ERR, "dTBT parent scope not valid\n");
+		return;
+	}
+
+	/* Scope */
+	acpigen_write_scope(parent_scope);
+	dtbt_write_dsd();
+
+	/* Device */
+	acpigen_write_device(dev_name);
+	acpigen_write_name_integer("_ADR", 0);
+	dtbt_write_opregion(bus);
+
+	/* Method */
+	acpigen_write_method_serialized("PTS", 0);
+
+	acpigen_write_debug_string("dTBT prepare to sleep");
+	acpigen_write_store_int_to_namestr(PCIE2TBT_GO2SX_NO_WAKE << 1, "P2TB");
+	acpigen_write_delay_until_namestr_int(GO2SX_TIMEOUT_MS, "TB2P", PCIE2TBT_GO2SX_NO_WAKE << 1);
+
+	acpigen_write_debug_namestr("TB2P");
+	acpigen_write_store_int_to_namestr(0, "P2TB");
+	acpigen_write_delay_until_namestr_int(GO2SX_TIMEOUT_MS, "TB2P", 0);
+	acpigen_write_debug_namestr("TB2P");
+
+	acpigen_write_method_end();
+	acpigen_write_device_end();
+	acpigen_write_scope_end();
+
+	printk(BIOS_DEBUG, "dTBT fill SSDT\n");
+	printk(BIOS_DEBUG, "  Dev %s\n", dev_path(dev));
+	//printk(BIOS_DEBUG, "  Bus %s\n", bus_path(bus));
+	printk(BIOS_DEBUG, "  Parent %s\n", dev_path(parent));
+	printk(BIOS_DEBUG, "  Scope %s\n", parent_scope);
+	printk(BIOS_DEBUG, "    Device %s\n", dev_name);
+
+	// \.TBTS Method
+	acpigen_write_scope("\\");
+	acpigen_write_method("TBTS", 0);
+	acpigen_emit_namestring(acpi_device_path_join(dev, "PTS"));
+	acpigen_write_method_end();
+	acpigen_write_scope_end();
+}
+
+static const char *dtbt_acpi_name(const struct device *dev)
+{
+	return "DTBT";
+}
+
+static struct pci_operations dtbt_device_ops_pci = {
+	.set_subsystem = 0,
+};
+
+static struct device_operations dtbt_device_ops = {
+	.read_resources   = pci_bus_read_resources,
+	.set_resources    = pci_dev_set_resources,
+	.enable_resources = pci_bus_enable_resources,
+	.acpi_fill_ssdt   = dtbt_fill_ssdt,
+	.acpi_name        = dtbt_acpi_name,
+	.scan_bus         = pciexp_scan_bridge,
+	.reset_bus        = pci_bus_reset,
+	.ops_pci          = &dtbt_device_ops_pci,
+};
+
+static void dtbt_enable(struct device *dev)
+{
+	if (!is_dev_enabled(dev) || dev->path.type != DEVICE_PATH_PCI)
+		return;
+
+	if (pci_read_config16(dev, PCI_VENDOR_ID) != PCI_VID_INTEL)
+		return;
+
+	// TODO: check device ID
+
+	dev->ops = &dtbt_device_ops;
+
+	printk(BIOS_INFO, "dTBT controller found at %s\n", dev_path(dev));
+
+	// XXX: Recommendation is to set SL1 ("User Authorization")
+	printk(BIOS_DEBUG, "dTBT set security level SL0\n");
+	dtbt_cmd(dev, PCIE2TBT_SET_SECURITY_LEVEL, 0, TIMEOUT_MS);
+	// XXX: Must verify change or rollback all controllers
+
+	if (acpi_is_wakeup_s3()) {
+		printk(BIOS_DEBUG, "dTBT SX exit\n");
+		dtbt_cmd(dev, PCIE2TBT_SX_EXIT_TBT_CONNECTED, 0, TIMEOUT_MS);
+		// TODO: "wait for fast link bring-up" loop (timeout: 5s)
+	} else {
+		printk(BIOS_DEBUG, "dTBT boot on\n");
+		dtbt_cmd(dev, PCIE2TBT_BOOT_ON, 0, TIMEOUT_MS);
+	}
+}
+
+struct chip_operations drivers_intel_dtbt_ops = {
+	.name = "Intel Discrete Thunderbolt",
+	.enable_dev = dtbt_enable,
+};
-- 
2.39.5

